This one, he says, is only 2.25" deep in between the fans.
http://cgi.ebay.com/ebaymotors/Dual-Ford-Electric-Fan-W-Relay-kit-mustang-chevy-dodge_W0QQcmdZViewItemQQhashZitem2c4fb1fdc3QQitemZ190315625923QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
This is the same guy...